Advertise virtually anything here, with CPM banner ads, CPM email ads and CPC contextual links. You can target relevant areas of the site and show ads based on geographical location of the user if you wish.

Depends upon the type of platform you are using. If you are using a CMS like Wordpress ,Joomla or Drupal or an ecommerce platform like Opencart,Magento,etc you cannot and should not use a static XML sitemap generated from tools as the site is always evolving and pages keep on adding.If you use a static sitemap for a dynamic site , everytime you add a page or resource you have to add that in the site map. All the above mentioned CMS and Ecommerce platform either come with inbuilt xml sitemap generator or have plugins to create this enhancement.

Remember that not only pages but other resources should be also listed in the sitemaps. Make sure you submit your sitemap to Google and Bing via there webmaster tools section.HTML sitemaps should always be there on the site as your site is not only for bots it is for humans primarily.

The Sitemaps protocol allows a webmaster to inform search engines about URLs on a website that are available for crawling. A Sitemap is an XML file that lists the URLs for a site.
The maximum Sitemap size of 10 MB or 50,000 URLs.

An XML sitemap:
- Ensures better visibility by search engines
- Enables you to rely less on external links that will bring search engines to your site.
- Helps with broken internal links or orphaned pages that cannot be reached in other way
- Alerts search engines to any changes/additions to your site.
- Helps you choose pages that you don’t want to index

We use sitemaps .org and you can set the sitemap creation/update by cronjob. We then add the sitemap URL to Google Analytics and all has been well. It updated regularly and new URLs and indexed rather quickly.

You can find lot many free plugin online which can create sitemap for your wordpress website.
I give you such name given below you just find it by name in wordpress plugin directory.
1.Google XML Sitemaps2.WP Sitemap Page
3.Yoast SEO

And If you don't want to use this so you can create without plugin also by using this website "xml-sitemaps.com" and upload it in your server.